XXIX.
THE LIKELIHOOD OF A JAPANESE ATTACK AT HAWAII AS ESTIMATED WASHINGTON DECEMBER
6, 1941
A.
NAVY ESTIMATES
Admiral
Stark testified that as of December 6, 1941, he considered that a United States
and Japanese war was imminent and that there was a strong probability that
Japan would strike. He thought that the Philippines and Guam were the most
likely targets, of United States territory. He considered that an air attack on
Pearl Harbor was possible but, he said, he thought that there was a good chance
that any attack there would be detected in time to intercept it or to reduce
its effectiveness (pages 73, 165) However, he had no information indicating
that such an attack on Pearl Harbor was probable (pages 105 792). Generally
speaking, he said, he and his advisors did not expect a raid on Hawaii (page
798).
Captain Wellborn said that there were various individuals in
the Navy Department who felt that an attack on Pearl Harbor was probable‑such
as Admiral Turner, and there were others who felt that it was less probable,
although possible, such as Admirals Ingersoll and Stark.
Admiral
Turner, on the other hand, testified that he had expected a landing in
Southeast Asia, attacks on the Philippines and some form of attack on Hawaii
525 CONGRESSIONAL
INVESTIGATION PEARL HARBOR ATTACK
(page 1002). He had
thought that an aerial torpedo attack in Pearl Harbor was not only possible
(page 997) but that it was a probability, and he was not surprised when it was
made (page 1021).
Captain Glover said that a daily short strategic summary of
the international military and political situation had been prepared by
Commander Ansel in collaboration with Captain Wright and submitted to Admiral
Turner. These are contained in a notebook entitled "Daily Information
Summary-Op 12" filed with the Combat Intelligence Section. Captain Glover
said that he did not believe that it had generally been felt by officers in the
Plans Division that the Japanese would strike as they did. (p. 176)
Admiral Turner said that he had always been of the view that
a torpedo plane attack on ships in Pearl Harbor was possible and pointed out
that the Bureau of Ordnance had modified its earlier letters indicating that
still 75' depth was necessary.
Admiral Turner said that the Chief of Naval Operations
shared his view as to the possibility of a surprise air attack on Pearl Harbor
and that they felt that Admiral Kimmel also had the same views. (p. 261)
Admiral Turner said that generally he thought our
Intelligence regarding Japanese intentions and activities was quite good. He
said that he had anticipated that the Japanese would attack the United States,
Great Britain and the Netherlands East Indies at the end of November 1941. The
attack of December 7 came as no surprise to him whatsoever nor, he said, was it
a surprise to the Chief of Naval Operations. He was not surprised by the
Japanese attack upon Pearl Harbor and pointed out that he had originated the
Secretary of the Navy's letter of January 1941, pointing out that just such an
attack was the most probable form that the initiation of war by Japan would
take. (p. 259)
Admiral Wilkinson recalled no specific evaluation as to the
capability of the Japanese to launch an attack such as the attack which was
made. (p. 287) Admiral Wilkinson said that he was not surprised by the fact
that the Japanese did venture a carrier raid, but was surprised by the force of
the raid, and by the fact that the attack had come in without detection. (p.
287‑8)
Admiral
Ingersoll stated that he had considered that a surprise attack on Pearl Harbor
was a possibility (page 821) but he had not thought that an air attack on Oahu
was probable. He had thought that when war came there would be numerous
Japanese submarines around Pearl Harbor and he expected raids against outlying islands
in the Fourteenth Naval District and that any attack on Hawaii would be by
submarines or surface forces (page 847). (3)
Admiral Ingersoll said that he thought the dispatches
concerning the reenforcement of Midway and Wake should have accentuated the
idea that there was a danger of raids in the area rather than allay suspicion
as to the probability of attack in the Hawaiian area. (p. 427)
Admiral Ingersoll said that the December 3 dispatch
indicated that war was imminent and a matter of a few days or hours and that it
was believed in the office of the Chief of Naval Operations that such war would
include the United States as indicated by the reference to Washington in that
dispatch. (p.428)
Admiral Ingersoll said that he recalled no discussion in
late November or early December regarding the probability of an air attack on
Hawaii. They did anticipate possible attacks by submarines and possible raids
either by light forces or by submarines at Wake, Midway and Johnston. (p. 426)
Admiral Ingersoll said that he expected that the Japanese
attack against the United States would be on the Philippines and Guam with
possible raiding attacks on our outlying islands to the westward of Hawaii and
submarine attacks against shipping around Hawaii and generally between the
west coast and the United States. He said that he did not recall anyone in
operations reporting to Admiral Stark that the war would be precipitated by an
air attack on Pearl Harbor. (p. 430)
Captain
Heard testified that they had no information which indicated or would lead to
an obvious conclusion that there was an impending attack on Hawaii. He was
quite convinced that war would start in Southeast Asia (page 468).
Admiral Wilkinson said
that for a month preceding 7 December 1941 there were no discussions in which
he participated regarding the likelihood of a Japanese move on Pearl Harbor.
He stated further that during the first week to
PROCEEDINGS OF
HEWITT INQUIRY 527
December, 1941, he remembered no
discussions concerning the question of whether or not aerial reconnaissance was
being conducted from Oahu (p. 396).
According
to Commander Kramer, from the information he saw there was not the slightest
indication of Japanese overt intention to attack the United States. The
information of this type was known to be incomplete and CNO knew this (page
985).
B.
ARMY ESTIMATE
General
Marshall said that he had felt that a Japanese attack would come in the Western
Pacific, also possibly against the Panama Canal, which was then closed to the
Japanese (page 861) The Japanese movements pointed to a move into Thailand,
action to cut off the Burma Road, and a threat to the Malay‑Kra
Peninsula, They had no indications of Japanese plans for assault on Hawaii
(page 860-1). He always was in fear of a surprise attack on United States
territory but the probabilities pointed to the Panama Canal and the Philippines
before Hawaii; there were no specific indications in the possession of the Army
and no reports from the Navy showing a threat against Hawaii (page 863). The
attack on Pearl Harbor came as a surprise to General Marshall (page 882). It
had appeared to him, as set forth in his letter in February 1941, that the possibility
in Hawaii in the way of attack was combined air and sabotage: There was a
strong probability—really a certainty—that there was an evil intent in the Far
East. The question was when it would explode and to what extent it would be on
an infiltration basis. As to probability, Siam, the Malaya Peninsula, and the
Panama Canal took priority, in his opinion, to Hawaii.
C.
STATE DEPARTMENT ESTIMATES
Ambassador
Grew said that he had received no report from the Korean underground that the
Japanese would attack Pearl Harbor and Mr. Hamilton said that he had felt that
the Japanese would move to the southward, but that he had not excluded from his
estimates an attack on United States possessions (page 1075).